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From: Muchun Song In-Reply-To: <875d80ee-d99a-4580-8648-36adb1e8591c@kylinos.cn> Date: Wed, 5 Mar 2025 14:46:02 +0800 Cc: Qi Zheng , akpm@linux-foundation.org, david@fromorbit.com, roman.gushchin@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <451E5C9A-F7FB-41DD-B760-25E4883B0861@linux.dev> References: <20250305020123.605496-1-liuye@kylinos.cn> <99A7645C-B8FB-4F28-B4B8-D5372F4C001E@linux.dev> <875d80ee-d99a-4580-8648-36adb1e8591c@kylinos.cn> To: liuye X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: B824EC000C X-Stat-Signature: ukg5ndymgy7uwpfzz4ybux9twyfg16jo X-Rspam-User: X-HE-Tag: 1741157208-641227 X-HE-Meta: U2FsdGVkX1+UQkrMv8UEhRPcIvliWKwdu4a11LEkwnCbrCkao4VbJn3w1UOe7g4/a7qa9LmMt8GMTdn4UWcHSxLzOIhQ1aK4ERjypck3riPOKK4ep9rxqMZc5+lVwdbXdDfpngp5XU/NiOS4+rQruy+62jUGHGzJX9hYtYn2QIMe1p+rhxzsWkguqOsNGapmLTe1HHHkEbk7qgei+TxFx5pWlSLySPezXZI8DQy3lnuxzkukUXUUDUBB2tFcBjh63ShwijeIQBh729SOlv2UAPo8rbLQOXLNdIXCIx4XKcSFIjaHSWhNuB91J0SOW1DaUvZ1slLlHsHoN/+cnQvQVHGTBeJ4NFX+WujU6zWl2IYIMLHL6N2P46iIJ+K9jC4a55Lk4STGs4Y/d0FOAKd2OInm0U0GQ5PdCKf2WLzqYrz7uDgHGq9aESS3dYN0rQcSR09YU50pW2YtocniJsc39KlnKy/hx7xDGeNgPTV0K13VKUPEsXjUbRtaP4sTwhcZTfBrT4952gkL2Ru2Iw1w3c8x3IuemsaaqtrHWkMYUSJgSG9k64bHy9wNYl0EkSZ5IDFkScVT6ZCCiibk9WzkFOGGxlxa3Ov4QWdmOK+oz271qsFglMZJTfTD7I2plB6ugNIBsPAgQP9bisf88SRtSN+XS6dCljThWkT86bEUFuig5a2chRP//JIcdPKrUIK3r+9j3Y6n3mjR0MJOCfyOVIdxwurNmjbSpmK8Rja+xz/sNiVvQtVlDi/qZxdITaxqL5+gP1vFr1Rzd23OLrzQaKhU+vR+TOJhtgqlFVH4Ec/MitLetjJRKkE7rr8WkbZRi0GqiBLWD5fYlSOOTANMBclez+7n07p6fgri+P2B4yLurzwbopSWHXciMxcAKBIMTYkf4aZvoWFKtk9ZqGxUzVBCPZu9g+pRnW3IHHVJXcdabSpVpKOredT8p2R+rJj6EK3Wzk0hj/O9KYljqeX I6oDSbdp J1rP4RvLKB+mBAMfsGI9wYPoJ/QSsmPI88cXdetptJ8IffD5aYmlJ1cGZYuI1sacPWAlCAAWMAUysHu1tU657cHP+E6qIxld/mRXRjbFNa6AiSoA0Xh1wiESpBfURI+Dwq/rMg1sST1/k+iNAxsOU/iFkPbDSuodHKO1kjmqZr5/b7jpByIQnaspvo6GUbRsn/Ie7nqfdmD+Otv6Akwhip6RPAOE1lfirqzoQ5tZmoSzdgBL5qcuUhucGuNIuQ2379P95arTYbvY66gDEMEI4ICND0HTq61VyK13pSmoF8xDbGk98KA3Sm+7tpQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > On Mar 5, 2025, at 14:10, liuye wrote: >=20 >=20 > =E5=9C=A8 2025/3/5 11:26, Qi Zheng =E5=86=99=E9=81=93: >>=20 >>=20 >> On 3/5/25 11:17 AM, Muchun Song wrote: >>>=20 >>>=20 >>>> On Mar 5, 2025, at 10:01, Liu Ye wrote:=20 >>>>=20 >>>> After calling debugfs_change_name function, the return value should = be=20 >>>> checked and the old name restored. If debugfs_change_name fails, = the new=20 >>>> name memory should be freed. >>>=20 >>> Seems it is not a big problem, no memory leak at least. The effect = is that=20 >>> the shrinker->name is not consistent with the name displayed in = debugfs.=20 >>> Right? But the improvement LGTM. So: >>=20 >> Right, so the subject needs to be changed.=20 >>=20 >> Maybe:=20 >>=20 >> mm: shrinker: fix name consistency issue in shrinker_debugfs_rename() >>=20 >> ? > I will send a new patch using this subject later. Please update the commit message as well to include the effect. > And add Reviewed-by=EF=BC=9AQi Zheng =EF=BC= =9F >=20 >>=20 >> BTW, it seems that the callers of shrinker_debugfs_rename() did not=20= >> process the return value of the function? >=20 > Yes, At the same time, I also found that many positions using=20 > debugfs_change_name did not determine the return value. >=20 >>=20 >>>=20 >>> Reviewed-by: Muchun Song =20 >>>=20 >>> Thanks. > Thanks. >>>=20 >>>>=20 >>>> Signed-off-by: Liu Ye =20 >>>> ---=20 >>>> mm/shrinker_debug.c | 8 ++++++--=20 >>>> 1 file changed, 6 insertions(+), 2 deletions(-)=20 >>>>=20 >>>> diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c=20 >>>> index 794bd433cce0..20eaee3e97f7 100644=20 >>>> --- a/mm/shrinker_debug.c=20 >>>> +++ b/mm/shrinker_debug.c=20 >>>> @@ -214,10 +214,14 @@ int shrinker_debugfs_rename(struct shrinker = *shrinker, const char *fmt, ...)=20 >>>> ret =3D debugfs_change_name(shrinker->debugfs_entry, "%s-%d",=20 >>>> shrinker->name, shrinker->debugfs_id);=20 >>>>=20 >>>> + if (ret) {=20 >>>> + shrinker->name =3D old;=20 >>>> + kfree_const(new);=20 >>>> + } else {=20 >>>> + kfree_const(old);=20 >>>> + }=20 >>>> mutex_unlock(&shrinker_mutex);=20 >>>>=20 >>>> - kfree_const(old);=20 >>>> -=20 >>>> return ret;=20 >>>> }=20 >>>> EXPORT_SYMBOL(shrinker_debugfs_rename);=20 >>>> --=20 >>>> 2.25.1=20 >>>>=20 >>>=20 >>=20